1. Field of the Invention
The present invention is directed to a pre-filled syringe assembly adapted for dispensing and delivery of a fluid. More particularly, the present invention is directed to a pre-filled syringe assembly having a tamper evident tip cap providing an indication if the contents of the syringe assembly have been compromised.
2. Description of Related Art
Conventional syringes are well known to be used in connection with a vial of a medication, where the user draws the fluid into the syringe immediately prior to injection and delivery of the fluid to the patient. Oftentimes, hypodermic syringes may be packaged as “pre-filled” devices, wherein the syringe is pre-filled with medication prior to being packaged and delivered to the end user. In this manner, there is no need for the user to fill the device prior to injection, thereby saving time for the end user and maintaining consistent volumes for delivery.
Pre-filled syringes and pre-filled metered dose syringes are often filled with narcotics or other drugs at a production facility, packaged, and then shipped to a medical facility. Once at the facility, these syringes are often placed in controlled storage and/or locked cabinets to reduce theft of the syringes themselves and/or theft of the contents of these syringes. Even though measures, such as controlled storage, are taken to ensure that the contents of these syringes remain intact, the risk still remains that the syringe contents can be tampered with and/or stolen and replaced with a saline solution. One technique for preventing tampering is the use of a snap cap for the tip cap that makes a snapping noise when removed from the syringe assembly. U.S. Pat. No. 4,667,837 to Vitello et al. discloses a tamper proof cap for a pre-filled syringe comprising a top member concentrically disposed in a generally cylindrical sleeve member and connected by frangible elements to the sleeve member. U.S. Pat. No. 7,041,087 to Henderson et al. discloses an outer cap for a pre-filled syringe that is covered with a cylindrical cover cap which connects with the top wall of a holding member through a frangible portion. The cylindrical cover cap may be broken from the top wall of the holding member for tampering prevention/tamper-proof evidence. One drawback to this type of system is that the contents of the syringe can be heated and the cap reapplied to “reset” it to its previously deformed state, or the user tampering with the device can use an additional syringe to create a vacuum inside the “tampered” syringe and reset the snap cap. Then, it appears as if the syringe has not been tampered with. In these tamper resistant systems, a shrink wrap band is required to show that the cap has not been altered. It is desirable to produce pre-filled syringes having a readily viewable, non-reversible tamper indicator that ensures the integrity of the syringe contents.